1. Field of the Invention
The present invention relates to automatic washing machines. More particularly the present invention relates to a method of automatically selecting a dishwashing cycle depending on a number of conditions. While the present invention is described as it applies to automatic dishwashers, it has equal applicability to all cycle controlled washing machines and other cycle controlled systems.
2. Problems in the Art
Prior art dishwashers typically have a number of user selectable dishwashing cycles. The user manually selects one of the cycles depending on what cycle the user feels is appropriate. For example, if the dishes in the dishwasher are not very dirty, the user might select a light washing cycle. On the other hand, if the dishes are very soiled, the user might pick a heavy wash cycle.
Prior art dishwashers have several disadvantages. First, when turning on the dishwasher, the operator may not know how soiled the dishes are without opening up the dishwasher and inspecting the dishes. Even then, visual inspection may not give a good indication of how dirty they are. Some dishes may be dirtier than others, making the user think that the entire load is either dirtier or cleaner than it really is. Also, there is no way for the user to be aware of other factors that affect the selection of the most effective and efficient washing cycle. Such factors include the amount of soil in the water, the presence of detergent in the water after the wash cycle starts, the water temperature, and other factors such as "starving" which is discussed below. In addition, the user may not know or remember how long the dishes have been in the dishwasher. The longer the dishes are in the dishwasher, the harder it is to clean the food off since the food will be dried on the dishes.
Another disadvantage of prior art dishwashers is the degree of complication in operating the dishwasher. When turning on the dishwasher, the user must choose between a number of settings without necessarily knowing which is the best setting. Users not familiar with the dishwasher may not know which setting is the most effective for any set of conditions.
In recent years, manufacturers have been able to make "smart" appliances which have the capability of automatically selecting cycles which were previously selected manually. In a "smart" appliance, the user need only activate a small number of buttons under normal operation. However, even with "smart" appliances, the effectiveness of the appliance is limited to the method used to select cycles. To be effective, an automatic appliance should select cycles based on all relevant operating conditions. In addition, with "smart" dishwashers, if the user is unsatisfied with the performance of the dishwasher, there is no way to improve the performance without manually selecting the wash cycles which defeats the purpose of having a "smart" dishwasher.